1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Extension Header handling for IPv6 4 * Linux INET6 implementation 5 * 6 * Authors: 7 * Pedro Roque <roque@di.fc.ul.pt> 8 * Andi Kleen <ak@muc.de> 9 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> 10 */ 11 12 /* Changes: 13 * yoshfuji : ensure not to overrun while parsing 14 * tlv options. 15 * Mitsuru KANDA @USAGI and: Remove ipv6_parse_exthdrs(). 16 * YOSHIFUJI Hideaki @USAGI Register inbound extension header 17 * handlers as inet6_protocol{}. 18 */ 19 20 #include <linux/errno.h> 21 #include <linux/types.h> 22 #include <linux/socket.h> 23 #include <linux/sockios.h> 24 #include <linux/net.h> 25 #include <linux/netdevice.h> 26 #include <linux/in6.h> 27 #include <linux/icmpv6.h> 28 #include <linux/slab.h> 29 #include <linux/export.h> 30 31 #include <net/dst.h> 32 #include <net/sock.h> 33 #include <net/snmp.h> 34 35 #include <net/ipv6.h> 36 #include <net/protocol.h> 37 #include <net/transp_v6.h> 38 #include <net/rawv6.h> 39 #include <net/ndisc.h> 40 #include <net/ip6_route.h> 41 #include <net/addrconf.h> 42 #include <net/calipso.h> 43 #if IS_ENABLED(CONFIG_IPV6_MIP6) 44 #include <net/xfrm.h> 45 #endif 46 #include <linux/seg6.h> 47 #include <net/seg6.h> 48 #ifdef CONFIG_IPV6_SEG6_HMAC 49 #include <net/seg6_hmac.h> 50 #endif 51 #include <net/rpl.h> 52 #include <linux/ioam6.h> 53 #include <net/ioam6.h> 54 #include <net/dst_metadata.h> 55 56 #include <linux/uaccess.h> 57 58 /********************* 59 Generic functions 60 *********************/ 61 62 /* An unknown option is detected, decide what to do */ 63 64 static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff, 65 bool disallow_unknowns) 66 { 67 if (disallow_unknowns) { 68 /* If unknown TLVs are disallowed by configuration 69 * then always silently drop packet. Note this also 70 * means no ICMP parameter problem is sent which 71 * could be a good property to mitigate a reflection DOS 72 * attack. 73 */ 74 75 goto drop; 76 } 77 78 switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) { 79 case 0: /* ignore */ 80 return true; 81 82 case 1: /* drop packet */ 83 break; 84 85 case 3: /* Send ICMP if not a multicast address and drop packet */ 86 /* Actually, it is redundant check. icmp_send 87 will recheck in any case. 88 */ 89 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) 90 break; 91 fallthrough; 92 case 2: /* send ICMP PARM PROB regardless and drop packet */ 93 icmpv6_param_prob_reason(skb, ICMPV6_UNK_OPTION, optoff, 94 SKB_DROP_REASON_UNHANDLED_PROTO); 95 return false; 96 } 97 98 drop: 99 kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO); 100 return false; 101 } 102 103 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff); 104 static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff); 105 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff); 106 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff); 107 #if IS_ENABLED(CONFIG_IPV6_MIP6) 108 static bool ipv6_dest_hao(struct sk_buff *skb, int optoff); 109 #endif 110 111 /* Parse tlv encoded option header (hop-by-hop or destination) */ 112 113 static bool ip6_parse_tlv(bool hopbyhop, 114 struct sk_buff *skb, 115 int max_count) 116 { 117 int len = (skb_transport_header(skb)[1] + 1) << 3; 118 const unsigned char *nh = skb_network_header(skb); 119 int off = skb_network_header_len(skb); 120 bool disallow_unknowns = false; 121 int tlv_count = 0; 122 int padlen = 0; 123 124 if (unlikely(max_count < 0)) { 125 disallow_unknowns = true; 126 max_count = -max_count; 127 } 128 129 if (skb_transport_offset(skb) + len > skb_headlen(skb)) 130 goto bad; 131 132 off += 2; 133 len -= 2; 134 135 while (len > 0) { 136 int optlen, i; 137 138 if (nh[off] == IPV6_TLV_PAD1) { 139 padlen++; 140 if (padlen > 7) 141 goto bad; 142 off++; 143 len--; 144 continue; 145 } 146 if (len < 2) 147 goto bad; 148 optlen = nh[off + 1] + 2; 149 if (optlen > len) 150 goto bad; 151 152 if (nh[off] == IPV6_TLV_PADN) { 153 /* RFC 2460 states that the purpose of PadN is 154 * to align the containing header to multiples 155 * of 8. 7 is therefore the highest valid value. 156 * See also RFC 4942, Section 2.1.9.5. 157 */ 158 padlen += optlen; 159 if (padlen > 7) 160 goto bad; 161 /* RFC 4942 recommends receiving hosts to 162 * actively check PadN payload to contain 163 * only zeroes. 164 */ 165 for (i = 2; i < optlen; i++) { 166 if (nh[off + i] != 0) 167 goto bad; 168 } 169 } else { 170 tlv_count++; 171 if (tlv_count > max_count) 172 goto bad; 173 174 if (hopbyhop) { 175 switch (nh[off]) { 176 case IPV6_TLV_ROUTERALERT: 177 if (!ipv6_hop_ra(skb, off)) 178 return false; 179 break; 180 case IPV6_TLV_IOAM: 181 if (!ipv6_hop_ioam(skb, off)) 182 return false; 183 break; 184 case IPV6_TLV_JUMBO: 185 if (!ipv6_hop_jumbo(skb, off)) 186 return false; 187 break; 188 case IPV6_TLV_CALIPSO: 189 if (!ipv6_hop_calipso(skb, off)) 190 return false; 191 break; 192 default: 193 if (!ip6_tlvopt_unknown(skb, off, 194 disallow_unknowns)) 195 return false; 196 break; 197 } 198 } else { 199 switch (nh[off]) { 200 #if IS_ENABLED(CONFIG_IPV6_MIP6) 201 case IPV6_TLV_HAO: 202 if (!ipv6_dest_hao(skb, off)) 203 return false; 204 break; 205 #endif 206 default: 207 if (!ip6_tlvopt_unknown(skb, off, 208 disallow_unknowns)) 209 return false; 210 break; 211 } 212 } 213 padlen = 0; 214 } 215 off += optlen; 216 len -= optlen; 217 } 218 219 if (len == 0) 220 return true; 221 bad: 222 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); 223 return false; 224 } 225 226 /***************************** 227 Destination options header. 228 *****************************/ 229 230 #if IS_ENABLED(CONFIG_IPV6_MIP6) 231 static bool ipv6_dest_hao(struct sk_buff *skb, int optoff) 232 { 233 struct ipv6_destopt_hao *hao; 234 struct inet6_skb_parm *opt = IP6CB(skb); 235 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 236 SKB_DR(reason); 237 int ret; 238 239 if (opt->dsthao) { 240 net_dbg_ratelimited("hao duplicated\n"); 241 goto discard; 242 } 243 opt->dsthao = opt->dst1; 244 opt->dst1 = 0; 245 246 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff); 247 248 if (hao->length != 16) { 249 net_dbg_ratelimited("hao invalid option length = %d\n", 250 hao->length); 251 SKB_DR_SET(reason, IP_INHDR); 252 goto discard; 253 } 254 255 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) { 256 net_dbg_ratelimited("hao is not an unicast addr: %pI6\n", 257 &hao->addr); 258 SKB_DR_SET(reason, INVALID_PROTO); 259 goto discard; 260 } 261 262 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr, 263 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS); 264 if (unlikely(ret < 0)) { 265 SKB_DR_SET(reason, XFRM_POLICY); 266 goto discard; 267 } 268 269 if (skb_cloned(skb)) { 270 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) 271 goto discard; 272 273 /* update all variable using below by copied skbuff */ 274 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + 275 optoff); 276 ipv6h = ipv6_hdr(skb); 277 } 278 279 if (skb->ip_summed == CHECKSUM_COMPLETE) 280 skb->ip_summed = CHECKSUM_NONE; 281 282 swap(ipv6h->saddr, hao->addr); 283 284 if (skb->tstamp == 0) 285 __net_timestamp(skb); 286 287 return true; 288 289 discard: 290 kfree_skb_reason(skb, reason); 291 return false; 292 } 293 #endif 294 295 static int ipv6_destopt_rcv(struct sk_buff *skb) 296 { 297 struct inet6_dev *idev = __in6_dev_get(skb->dev); 298 struct inet6_skb_parm *opt = IP6CB(skb); 299 #if IS_ENABLED(CONFIG_IPV6_MIP6) 300 __u16 dstbuf; 301 #endif 302 struct dst_entry *dst = skb_dst(skb); 303 struct net *net = dev_net(skb->dev); 304 int extlen; 305 306 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 307 !pskb_may_pull(skb, (skb_transport_offset(skb) + 308 ((skb_transport_header(skb)[1] + 1) << 3)))) { 309 __IP6_INC_STATS(dev_net(dst->dev), idev, 310 IPSTATS_MIB_INHDRERRORS); 311 fail_and_free: 312 kfree_skb(skb); 313 return -1; 314 } 315 316 extlen = (skb_transport_header(skb)[1] + 1) << 3; 317 if (extlen > net->ipv6.sysctl.max_dst_opts_len) 318 goto fail_and_free; 319 320 opt->lastopt = opt->dst1 = skb_network_header_len(skb); 321 #if IS_ENABLED(CONFIG_IPV6_MIP6) 322 dstbuf = opt->dst1; 323 #endif 324 325 if (ip6_parse_tlv(false, skb, net->ipv6.sysctl.max_dst_opts_cnt)) { 326 skb->transport_header += extlen; 327 opt = IP6CB(skb); 328 #if IS_ENABLED(CONFIG_IPV6_MIP6) 329 opt->nhoff = dstbuf; 330 #else 331 opt->nhoff = opt->dst1; 332 #endif 333 return 1; 334 } 335 336 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 337 return -1; 338 } 339 340 static void seg6_update_csum(struct sk_buff *skb) 341 { 342 struct ipv6_sr_hdr *hdr; 343 struct in6_addr *addr; 344 __be32 from, to; 345 346 /* srh is at transport offset and seg_left is already decremented 347 * but daddr is not yet updated with next segment 348 */ 349 350 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 351 addr = hdr->segments + hdr->segments_left; 352 353 hdr->segments_left++; 354 from = *(__be32 *)hdr; 355 356 hdr->segments_left--; 357 to = *(__be32 *)hdr; 358 359 /* update skb csum with diff resulting from seg_left decrement */ 360 361 update_csum_diff4(skb, from, to); 362 363 /* compute csum diff between current and next segment and update */ 364 365 update_csum_diff16(skb, (__be32 *)(&ipv6_hdr(skb)->daddr), 366 (__be32 *)addr); 367 } 368 369 static int ipv6_srh_rcv(struct sk_buff *skb) 370 { 371 struct inet6_skb_parm *opt = IP6CB(skb); 372 struct net *net = dev_net(skb->dev); 373 struct ipv6_sr_hdr *hdr; 374 struct inet6_dev *idev; 375 struct in6_addr *addr; 376 int accept_seg6; 377 378 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 379 380 idev = __in6_dev_get(skb->dev); 381 382 accept_seg6 = net->ipv6.devconf_all->seg6_enabled; 383 if (accept_seg6 > idev->cnf.seg6_enabled) 384 accept_seg6 = idev->cnf.seg6_enabled; 385 386 if (!accept_seg6) { 387 kfree_skb(skb); 388 return -1; 389 } 390 391 #ifdef CONFIG_IPV6_SEG6_HMAC 392 if (!seg6_hmac_validate_skb(skb)) { 393 kfree_skb(skb); 394 return -1; 395 } 396 #endif 397 398 looped_back: 399 if (hdr->segments_left == 0) { 400 if (hdr->nexthdr == NEXTHDR_IPV6 || hdr->nexthdr == NEXTHDR_IPV4) { 401 int offset = (hdr->hdrlen + 1) << 3; 402 403 skb_postpull_rcsum(skb, skb_network_header(skb), 404 skb_network_header_len(skb)); 405 406 if (!pskb_pull(skb, offset)) { 407 kfree_skb(skb); 408 return -1; 409 } 410 skb_postpull_rcsum(skb, skb_transport_header(skb), 411 offset); 412 413 skb_reset_network_header(skb); 414 skb_reset_transport_header(skb); 415 skb->encapsulation = 0; 416 if (hdr->nexthdr == NEXTHDR_IPV4) 417 skb->protocol = htons(ETH_P_IP); 418 __skb_tunnel_rx(skb, skb->dev, net); 419 420 netif_rx(skb); 421 return -1; 422 } 423 424 opt->srcrt = skb_network_header_len(skb); 425 opt->lastopt = opt->srcrt; 426 skb->transport_header += (hdr->hdrlen + 1) << 3; 427 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 428 429 return 1; 430 } 431 432 if (hdr->segments_left >= (hdr->hdrlen >> 1)) { 433 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 434 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 435 ((&hdr->segments_left) - 436 skb_network_header(skb))); 437 return -1; 438 } 439 440 if (skb_cloned(skb)) { 441 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 442 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 443 IPSTATS_MIB_OUTDISCARDS); 444 kfree_skb(skb); 445 return -1; 446 } 447 } 448 449 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); 450 451 hdr->segments_left--; 452 addr = hdr->segments + hdr->segments_left; 453 454 skb_push(skb, sizeof(struct ipv6hdr)); 455 456 if (skb->ip_summed == CHECKSUM_COMPLETE) 457 seg6_update_csum(skb); 458 459 ipv6_hdr(skb)->daddr = *addr; 460 461 ip6_route_input(skb); 462 463 if (skb_dst(skb)->error) { 464 dst_input(skb); 465 return -1; 466 } 467 468 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) { 469 if (ipv6_hdr(skb)->hop_limit <= 1) { 470 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 471 icmpv6_send(skb, ICMPV6_TIME_EXCEED, 472 ICMPV6_EXC_HOPLIMIT, 0); 473 kfree_skb(skb); 474 return -1; 475 } 476 ipv6_hdr(skb)->hop_limit--; 477 478 skb_pull(skb, sizeof(struct ipv6hdr)); 479 goto looped_back; 480 } 481 482 dst_input(skb); 483 484 return -1; 485 } 486 487 static int ipv6_rpl_srh_rcv(struct sk_buff *skb) 488 { 489 struct ipv6_rpl_sr_hdr *hdr, *ohdr, *chdr; 490 struct inet6_skb_parm *opt = IP6CB(skb); 491 struct net *net = dev_net(skb->dev); 492 struct inet6_dev *idev; 493 struct ipv6hdr *oldhdr; 494 unsigned char *buf; 495 int accept_rpl_seg; 496 int i, err; 497 u64 n = 0; 498 u32 r; 499 500 idev = __in6_dev_get(skb->dev); 501 502 accept_rpl_seg = net->ipv6.devconf_all->rpl_seg_enabled; 503 if (accept_rpl_seg > idev->cnf.rpl_seg_enabled) 504 accept_rpl_seg = idev->cnf.rpl_seg_enabled; 505 506 if (!accept_rpl_seg) { 507 kfree_skb(skb); 508 return -1; 509 } 510 511 looped_back: 512 hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb); 513 514 if (hdr->segments_left == 0) { 515 if (hdr->nexthdr == NEXTHDR_IPV6) { 516 int offset = (hdr->hdrlen + 1) << 3; 517 518 skb_postpull_rcsum(skb, skb_network_header(skb), 519 skb_network_header_len(skb)); 520 521 if (!pskb_pull(skb, offset)) { 522 kfree_skb(skb); 523 return -1; 524 } 525 skb_postpull_rcsum(skb, skb_transport_header(skb), 526 offset); 527 528 skb_reset_network_header(skb); 529 skb_reset_transport_header(skb); 530 skb->encapsulation = 0; 531 532 __skb_tunnel_rx(skb, skb->dev, net); 533 534 netif_rx(skb); 535 return -1; 536 } 537 538 opt->srcrt = skb_network_header_len(skb); 539 opt->lastopt = opt->srcrt; 540 skb->transport_header += (hdr->hdrlen + 1) << 3; 541 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 542 543 return 1; 544 } 545 546 if (!pskb_may_pull(skb, sizeof(*hdr))) { 547 kfree_skb(skb); 548 return -1; 549 } 550 551 n = (hdr->hdrlen << 3) - hdr->pad - (16 - hdr->cmpre); 552 r = do_div(n, (16 - hdr->cmpri)); 553 /* checks if calculation was without remainder and n fits into 554 * unsigned char which is segments_left field. Should not be 555 * higher than that. 556 */ 557 if (r || (n + 1) > 255) { 558 kfree_skb(skb); 559 return -1; 560 } 561 562 if (hdr->segments_left > n + 1) { 563 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 564 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 565 ((&hdr->segments_left) - 566 skb_network_header(skb))); 567 return -1; 568 } 569 570 if (!pskb_may_pull(skb, ipv6_rpl_srh_size(n, hdr->cmpri, 571 hdr->cmpre))) { 572 kfree_skb(skb); 573 return -1; 574 } 575 576 hdr->segments_left--; 577 i = n - hdr->segments_left; 578 579 buf = kcalloc(struct_size(hdr, segments.addr, n + 2), 2, GFP_ATOMIC); 580 if (unlikely(!buf)) { 581 kfree_skb(skb); 582 return -1; 583 } 584 585 ohdr = (struct ipv6_rpl_sr_hdr *)buf; 586 ipv6_rpl_srh_decompress(ohdr, hdr, &ipv6_hdr(skb)->daddr, n); 587 chdr = (struct ipv6_rpl_sr_hdr *)(buf + ((ohdr->hdrlen + 1) << 3)); 588 589 if ((ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST) || 590 (ipv6_addr_type(&ohdr->rpl_segaddr[i]) & IPV6_ADDR_MULTICAST)) { 591 kfree_skb(skb); 592 kfree(buf); 593 return -1; 594 } 595 596 err = ipv6_chk_rpl_srh_loop(net, ohdr->rpl_segaddr, n + 1); 597 if (err) { 598 icmpv6_send(skb, ICMPV6_PARAMPROB, 0, 0); 599 kfree_skb(skb); 600 kfree(buf); 601 return -1; 602 } 603 604 swap(ipv6_hdr(skb)->daddr, ohdr->rpl_segaddr[i]); 605 606 ipv6_rpl_srh_compress(chdr, ohdr, &ipv6_hdr(skb)->daddr, n); 607 608 oldhdr = ipv6_hdr(skb); 609 610 skb_pull(skb, ((hdr->hdrlen + 1) << 3)); 611 skb_postpull_rcsum(skb, oldhdr, 612 sizeof(struct ipv6hdr) + ((hdr->hdrlen + 1) << 3)); 613 if (unlikely(!hdr->segments_left)) { 614 if (pskb_expand_head(skb, sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3), 0, 615 GFP_ATOMIC)) { 616 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_OUTDISCARDS); 617 kfree_skb(skb); 618 kfree(buf); 619 return -1; 620 } 621 622 oldhdr = ipv6_hdr(skb); 623 } 624 skb_push(skb, ((chdr->hdrlen + 1) << 3) + sizeof(struct ipv6hdr)); 625 skb_reset_network_header(skb); 626 skb_mac_header_rebuild(skb); 627 skb_set_transport_header(skb, sizeof(struct ipv6hdr)); 628 629 memmove(ipv6_hdr(skb), oldhdr, sizeof(struct ipv6hdr)); 630 memcpy(skb_transport_header(skb), chdr, (chdr->hdrlen + 1) << 3); 631 632 ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); 633 skb_postpush_rcsum(skb, ipv6_hdr(skb), 634 sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3)); 635 636 kfree(buf); 637 638 skb_dst_drop(skb); 639 640 ip6_route_input(skb); 641 642 if (skb_dst(skb)->error) { 643 dst_input(skb); 644 return -1; 645 } 646 647 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) { 648 if (ipv6_hdr(skb)->hop_limit <= 1) { 649 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 650 icmpv6_send(skb, ICMPV6_TIME_EXCEED, 651 ICMPV6_EXC_HOPLIMIT, 0); 652 kfree_skb(skb); 653 return -1; 654 } 655 ipv6_hdr(skb)->hop_limit--; 656 657 skb_pull(skb, sizeof(struct ipv6hdr)); 658 goto looped_back; 659 } 660 661 dst_input(skb); 662 663 return -1; 664 } 665 666 /******************************** 667 Routing header. 668 ********************************/ 669 670 /* called with rcu_read_lock() */ 671 static int ipv6_rthdr_rcv(struct sk_buff *skb) 672 { 673 struct inet6_dev *idev = __in6_dev_get(skb->dev); 674 struct inet6_skb_parm *opt = IP6CB(skb); 675 struct in6_addr *addr = NULL; 676 struct in6_addr daddr; 677 int n, i; 678 struct ipv6_rt_hdr *hdr; 679 struct rt0_hdr *rthdr; 680 struct net *net = dev_net(skb->dev); 681 int accept_source_route = net->ipv6.devconf_all->accept_source_route; 682 683 if (idev && accept_source_route > idev->cnf.accept_source_route) 684 accept_source_route = idev->cnf.accept_source_route; 685 686 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || 687 !pskb_may_pull(skb, (skb_transport_offset(skb) + 688 ((skb_transport_header(skb)[1] + 1) << 3)))) { 689 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 690 kfree_skb(skb); 691 return -1; 692 } 693 694 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 695 696 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) || 697 skb->pkt_type != PACKET_HOST) { 698 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 699 kfree_skb(skb); 700 return -1; 701 } 702 703 switch (hdr->type) { 704 case IPV6_SRCRT_TYPE_4: 705 /* segment routing */ 706 return ipv6_srh_rcv(skb); 707 case IPV6_SRCRT_TYPE_3: 708 /* rpl segment routing */ 709 return ipv6_rpl_srh_rcv(skb); 710 default: 711 break; 712 } 713 714 looped_back: 715 if (hdr->segments_left == 0) { 716 switch (hdr->type) { 717 #if IS_ENABLED(CONFIG_IPV6_MIP6) 718 case IPV6_SRCRT_TYPE_2: 719 /* Silently discard type 2 header unless it was 720 * processed by own 721 */ 722 if (!addr) { 723 __IP6_INC_STATS(net, idev, 724 IPSTATS_MIB_INADDRERRORS); 725 kfree_skb(skb); 726 return -1; 727 } 728 break; 729 #endif 730 default: 731 break; 732 } 733 734 opt->lastopt = opt->srcrt = skb_network_header_len(skb); 735 skb->transport_header += (hdr->hdrlen + 1) << 3; 736 opt->dst0 = opt->dst1; 737 opt->dst1 = 0; 738 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); 739 return 1; 740 } 741 742 switch (hdr->type) { 743 #if IS_ENABLED(CONFIG_IPV6_MIP6) 744 case IPV6_SRCRT_TYPE_2: 745 if (accept_source_route < 0) 746 goto unknown_rh; 747 /* Silently discard invalid RTH type 2 */ 748 if (hdr->hdrlen != 2 || hdr->segments_left != 1) { 749 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 750 kfree_skb(skb); 751 return -1; 752 } 753 break; 754 #endif 755 default: 756 goto unknown_rh; 757 } 758 759 /* 760 * This is the routing header forwarding algorithm from 761 * RFC 2460, page 16. 762 */ 763 764 n = hdr->hdrlen >> 1; 765 766 if (hdr->segments_left > n) { 767 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 768 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 769 ((&hdr->segments_left) - 770 skb_network_header(skb))); 771 return -1; 772 } 773 774 /* We are about to mangle packet header. Be careful! 775 Do not damage packets queued somewhere. 776 */ 777 if (skb_cloned(skb)) { 778 /* the copy is a forwarded packet */ 779 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 780 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 781 IPSTATS_MIB_OUTDISCARDS); 782 kfree_skb(skb); 783 return -1; 784 } 785 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); 786 } 787 788 if (skb->ip_summed == CHECKSUM_COMPLETE) 789 skb->ip_summed = CHECKSUM_NONE; 790 791 i = n - --hdr->segments_left; 792 793 rthdr = (struct rt0_hdr *) hdr; 794 addr = rthdr->addr; 795 addr += i - 1; 796 797 switch (hdr->type) { 798 #if IS_ENABLED(CONFIG_IPV6_MIP6) 799 case IPV6_SRCRT_TYPE_2: 800 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr, 801 (xfrm_address_t *)&ipv6_hdr(skb)->saddr, 802 IPPROTO_ROUTING) < 0) { 803 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 804 kfree_skb(skb); 805 return -1; 806 } 807 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) { 808 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 809 kfree_skb(skb); 810 return -1; 811 } 812 break; 813 #endif 814 default: 815 break; 816 } 817 818 if (ipv6_addr_is_multicast(addr)) { 819 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 820 kfree_skb(skb); 821 return -1; 822 } 823 824 daddr = *addr; 825 *addr = ipv6_hdr(skb)->daddr; 826 ipv6_hdr(skb)->daddr = daddr; 827 828 ip6_route_input(skb); 829 if (skb_dst(skb)->error) { 830 skb_push(skb, skb->data - skb_network_header(skb)); 831 dst_input(skb); 832 return -1; 833 } 834 835 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) { 836 if (ipv6_hdr(skb)->hop_limit <= 1) { 837 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 838 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 839 0); 840 kfree_skb(skb); 841 return -1; 842 } 843 ipv6_hdr(skb)->hop_limit--; 844 goto looped_back; 845 } 846 847 skb_push(skb, skb->data - skb_network_header(skb)); 848 dst_input(skb); 849 return -1; 850 851 unknown_rh: 852 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 853 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 854 (&hdr->type) - skb_network_header(skb)); 855 return -1; 856 } 857 858 static const struct inet6_protocol rthdr_protocol = { 859 .handler = ipv6_rthdr_rcv, 860 .flags = INET6_PROTO_NOPOLICY, 861 }; 862 863 static const struct inet6_protocol destopt_protocol = { 864 .handler = ipv6_destopt_rcv, 865 .flags = INET6_PROTO_NOPOLICY, 866 }; 867 868 static const struct inet6_protocol nodata_protocol = { 869 .handler = dst_discard, 870 .flags = INET6_PROTO_NOPOLICY, 871 }; 872 873 int __init ipv6_exthdrs_init(void) 874 { 875 int ret; 876 877 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING); 878 if (ret) 879 goto out; 880 881 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 882 if (ret) 883 goto out_rthdr; 884 885 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE); 886 if (ret) 887 goto out_destopt; 888 889 out: 890 return ret; 891 out_destopt: 892 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 893 out_rthdr: 894 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 895 goto out; 896 }; 897 898 void ipv6_exthdrs_exit(void) 899 { 900 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE); 901 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS); 902 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING); 903 } 904 905 /********************************** 906 Hop-by-hop options. 907 **********************************/ 908 909 /* 910 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input(). 911 */ 912 static inline struct net *ipv6_skb_net(struct sk_buff *skb) 913 { 914 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev); 915 } 916 917 /* Router Alert as of RFC 2711 */ 918 919 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff) 920 { 921 const unsigned char *nh = skb_network_header(skb); 922 923 if (nh[optoff + 1] == 2) { 924 IP6CB(skb)->flags |= IP6SKB_ROUTERALERT; 925 memcpy(&IP6CB(skb)->ra, nh + optoff + 2, sizeof(IP6CB(skb)->ra)); 926 return true; 927 } 928 net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n", 929 nh[optoff + 1]); 930 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); 931 return false; 932 } 933 934 /* IOAM */ 935 936 static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff) 937 { 938 struct ioam6_trace_hdr *trace; 939 struct ioam6_namespace *ns; 940 struct ioam6_hdr *hdr; 941 942 /* Bad alignment (must be 4n-aligned) */ 943 if (optoff & 3) 944 goto drop; 945 946 /* Ignore if IOAM is not enabled on ingress */ 947 if (!__in6_dev_get(skb->dev)->cnf.ioam6_enabled) 948 goto ignore; 949 950 /* Truncated Option header */ 951 hdr = (struct ioam6_hdr *)(skb_network_header(skb) + optoff); 952 if (hdr->opt_len < 2) 953 goto drop; 954 955 switch (hdr->type) { 956 case IOAM6_TYPE_PREALLOC: 957 /* Truncated Pre-allocated Trace header */ 958 if (hdr->opt_len < 2 + sizeof(*trace)) 959 goto drop; 960 961 /* Malformed Pre-allocated Trace header */ 962 trace = (struct ioam6_trace_hdr *)((u8 *)hdr + sizeof(*hdr)); 963 if (hdr->opt_len < 2 + sizeof(*trace) + trace->remlen * 4) 964 goto drop; 965 966 /* Ignore if the IOAM namespace is unknown */ 967 ns = ioam6_namespace(ipv6_skb_net(skb), trace->namespace_id); 968 if (!ns) 969 goto ignore; 970 971 if (!skb_valid_dst(skb)) 972 ip6_route_input(skb); 973 974 ioam6_fill_trace_data(skb, ns, trace, true); 975 break; 976 default: 977 break; 978 } 979 980 ignore: 981 return true; 982 983 drop: 984 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); 985 return false; 986 } 987 988 /* Jumbo payload */ 989 990 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff) 991 { 992 const unsigned char *nh = skb_network_header(skb); 993 SKB_DR(reason); 994 u32 pkt_len; 995 996 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) { 997 net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", 998 nh[optoff+1]); 999 SKB_DR_SET(reason, IP_INHDR); 1000 goto drop; 1001 } 1002 1003 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2)); 1004 if (pkt_len <= IPV6_MAXPLEN) { 1005 icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, optoff + 2, 1006 SKB_DROP_REASON_IP_INHDR); 1007 return false; 1008 } 1009 if (ipv6_hdr(skb)->payload_len) { 1010 icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, optoff, 1011 SKB_DROP_REASON_IP_INHDR); 1012 return false; 1013 } 1014 1015 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { 1016 SKB_DR_SET(reason, PKT_TOO_SMALL); 1017 goto drop; 1018 } 1019 1020 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) 1021 goto drop; 1022 1023 IP6CB(skb)->flags |= IP6SKB_JUMBOGRAM; 1024 return true; 1025 1026 drop: 1027 kfree_skb_reason(skb, reason); 1028 return false; 1029 } 1030 1031 /* CALIPSO RFC 5570 */ 1032 1033 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff) 1034 { 1035 const unsigned char *nh = skb_network_header(skb); 1036 1037 if (nh[optoff + 1] < 8) 1038 goto drop; 1039 1040 if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1]) 1041 goto drop; 1042 1043 if (!calipso_validate(skb, nh + optoff)) 1044 goto drop; 1045 1046 return true; 1047 1048 drop: 1049 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); 1050 return false; 1051 } 1052 1053 int ipv6_parse_hopopts(struct sk_buff *skb) 1054 { 1055 struct inet6_skb_parm *opt = IP6CB(skb); 1056 struct net *net = dev_net(skb->dev); 1057 int extlen; 1058 1059 /* 1060 * skb_network_header(skb) is equal to skb->data, and 1061 * skb_network_header_len(skb) is always equal to 1062 * sizeof(struct ipv6hdr) by definition of 1063 * hop-by-hop options. 1064 */ 1065 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) || 1066 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) + 1067 ((skb_transport_header(skb)[1] + 1) << 3)))) { 1068 fail_and_free: 1069 kfree_skb(skb); 1070 return -1; 1071 } 1072 1073 extlen = (skb_transport_header(skb)[1] + 1) << 3; 1074 if (extlen > net->ipv6.sysctl.max_hbh_opts_len) 1075 goto fail_and_free; 1076 1077 opt->flags |= IP6SKB_HOPBYHOP; 1078 if (ip6_parse_tlv(true, skb, net->ipv6.sysctl.max_hbh_opts_cnt)) { 1079 skb->transport_header += extlen; 1080 opt = IP6CB(skb); 1081 opt->nhoff = sizeof(struct ipv6hdr); 1082 return 1; 1083 } 1084 return -1; 1085 } 1086 1087 /* 1088 * Creating outbound headers. 1089 * 1090 * "build" functions work when skb is filled from head to tail (datagram) 1091 * "push" functions work when headers are added from tail to head (tcp) 1092 * 1093 * In both cases we assume, that caller reserved enough room 1094 * for headers. 1095 */ 1096 1097 static void ipv6_push_rthdr0(struct sk_buff *skb, u8 *proto, 1098 struct ipv6_rt_hdr *opt, 1099 struct in6_addr **addr_p, struct in6_addr *saddr) 1100 { 1101 struct rt0_hdr *phdr, *ihdr; 1102 int hops; 1103 1104 ihdr = (struct rt0_hdr *) opt; 1105 1106 phdr = skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); 1107 memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); 1108 1109 hops = ihdr->rt_hdr.hdrlen >> 1; 1110 1111 if (hops > 1) 1112 memcpy(phdr->addr, ihdr->addr + 1, 1113 (hops - 1) * sizeof(struct in6_addr)); 1114 1115 phdr->addr[hops - 1] = **addr_p; 1116 *addr_p = ihdr->addr; 1117 1118 phdr->rt_hdr.nexthdr = *proto; 1119 *proto = NEXTHDR_ROUTING; 1120 } 1121 1122 static void ipv6_push_rthdr4(struct sk_buff *skb, u8 *proto, 1123 struct ipv6_rt_hdr *opt, 1124 struct in6_addr **addr_p, struct in6_addr *saddr) 1125 { 1126 struct ipv6_sr_hdr *sr_phdr, *sr_ihdr; 1127 int plen, hops; 1128 1129 sr_ihdr = (struct ipv6_sr_hdr *)opt; 1130 plen = (sr_ihdr->hdrlen + 1) << 3; 1131 1132 sr_phdr = skb_push(skb, plen); 1133 memcpy(sr_phdr, sr_ihdr, sizeof(struct ipv6_sr_hdr)); 1134 1135 hops = sr_ihdr->first_segment + 1; 1136 memcpy(sr_phdr->segments + 1, sr_ihdr->segments + 1, 1137 (hops - 1) * sizeof(struct in6_addr)); 1138 1139 sr_phdr->segments[0] = **addr_p; 1140 *addr_p = &sr_ihdr->segments[sr_ihdr->segments_left]; 1141 1142 if (sr_ihdr->hdrlen > hops * 2) { 1143 int tlvs_offset, tlvs_length; 1144 1145 tlvs_offset = (1 + hops * 2) << 3; 1146 tlvs_length = (sr_ihdr->hdrlen - hops * 2) << 3; 1147 memcpy((char *)sr_phdr + tlvs_offset, 1148 (char *)sr_ihdr + tlvs_offset, tlvs_length); 1149 } 1150 1151 #ifdef CONFIG_IPV6_SEG6_HMAC 1152 if (sr_has_hmac(sr_phdr)) { 1153 struct net *net = NULL; 1154 1155 if (skb->dev) 1156 net = dev_net(skb->dev); 1157 else if (skb->sk) 1158 net = sock_net(skb->sk); 1159 1160 WARN_ON(!net); 1161 1162 if (net) 1163 seg6_push_hmac(net, saddr, sr_phdr); 1164 } 1165 #endif 1166 1167 sr_phdr->nexthdr = *proto; 1168 *proto = NEXTHDR_ROUTING; 1169 } 1170 1171 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto, 1172 struct ipv6_rt_hdr *opt, 1173 struct in6_addr **addr_p, struct in6_addr *saddr) 1174 { 1175 switch (opt->type) { 1176 case IPV6_SRCRT_TYPE_0: 1177 case IPV6_SRCRT_STRICT: 1178 case IPV6_SRCRT_TYPE_2: 1179 ipv6_push_rthdr0(skb, proto, opt, addr_p, saddr); 1180 break; 1181 case IPV6_SRCRT_TYPE_4: 1182 ipv6_push_rthdr4(skb, proto, opt, addr_p, saddr); 1183 break; 1184 default: 1185 break; 1186 } 1187 } 1188 1189 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt) 1190 { 1191 struct ipv6_opt_hdr *h = skb_push(skb, ipv6_optlen(opt)); 1192 1193 memcpy(h, opt, ipv6_optlen(opt)); 1194 h->nexthdr = *proto; 1195 *proto = type; 1196 } 1197 1198 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, 1199 u8 *proto, 1200 struct in6_addr **daddr, struct in6_addr *saddr) 1201 { 1202 if (opt->srcrt) { 1203 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr, saddr); 1204 /* 1205 * IPV6_RTHDRDSTOPTS is ignored 1206 * unless IPV6_RTHDR is set (RFC3542). 1207 */ 1208 if (opt->dst0opt) 1209 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); 1210 } 1211 if (opt->hopopt) 1212 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); 1213 } 1214 1215 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto) 1216 { 1217 if (opt->dst1opt) 1218 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); 1219 } 1220 EXPORT_SYMBOL(ipv6_push_frag_opts); 1221 1222 struct ipv6_txoptions * 1223 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) 1224 { 1225 struct ipv6_txoptions *opt2; 1226 1227 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC); 1228 if (opt2) { 1229 long dif = (char *)opt2 - (char *)opt; 1230 memcpy(opt2, opt, opt->tot_len); 1231 if (opt2->hopopt) 1232 *((char **)&opt2->hopopt) += dif; 1233 if (opt2->dst0opt) 1234 *((char **)&opt2->dst0opt) += dif; 1235 if (opt2->dst1opt) 1236 *((char **)&opt2->dst1opt) += dif; 1237 if (opt2->srcrt) 1238 *((char **)&opt2->srcrt) += dif; 1239 refcount_set(&opt2->refcnt, 1); 1240 } 1241 return opt2; 1242 } 1243 EXPORT_SYMBOL_GPL(ipv6_dup_options); 1244 1245 static void ipv6_renew_option(int renewtype, 1246 struct ipv6_opt_hdr **dest, 1247 struct ipv6_opt_hdr *old, 1248 struct ipv6_opt_hdr *new, 1249 int newtype, char **p) 1250 { 1251 struct ipv6_opt_hdr *src; 1252 1253 src = (renewtype == newtype ? new : old); 1254 if (!src) 1255 return; 1256 1257 memcpy(*p, src, ipv6_optlen(src)); 1258 *dest = (struct ipv6_opt_hdr *)*p; 1259 *p += CMSG_ALIGN(ipv6_optlen(*dest)); 1260 } 1261 1262 /** 1263 * ipv6_renew_options - replace a specific ext hdr with a new one. 1264 * 1265 * @sk: sock from which to allocate memory 1266 * @opt: original options 1267 * @newtype: option type to replace in @opt 1268 * @newopt: new option of type @newtype to replace (user-mem) 1269 * 1270 * Returns a new set of options which is a copy of @opt with the 1271 * option type @newtype replaced with @newopt. 1272 * 1273 * @opt may be NULL, in which case a new set of options is returned 1274 * containing just @newopt. 1275 * 1276 * @newopt may be NULL, in which case the specified option type is 1277 * not copied into the new set of options. 1278 * 1279 * The new set of options is allocated from the socket option memory 1280 * buffer of @sk. 1281 */ 1282 struct ipv6_txoptions * 1283 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, 1284 int newtype, struct ipv6_opt_hdr *newopt) 1285 { 1286 int tot_len = 0; 1287 char *p; 1288 struct ipv6_txoptions *opt2; 1289 1290 if (opt) { 1291 if (newtype != IPV6_HOPOPTS && opt->hopopt) 1292 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); 1293 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) 1294 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); 1295 if (newtype != IPV6_RTHDR && opt->srcrt) 1296 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); 1297 if (newtype != IPV6_DSTOPTS && opt->dst1opt) 1298 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); 1299 } 1300 1301 if (newopt) 1302 tot_len += CMSG_ALIGN(ipv6_optlen(newopt)); 1303 1304 if (!tot_len) 1305 return NULL; 1306 1307 tot_len += sizeof(*opt2); 1308 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); 1309 if (!opt2) 1310 return ERR_PTR(-ENOBUFS); 1311 1312 memset(opt2, 0, tot_len); 1313 refcount_set(&opt2->refcnt, 1); 1314 opt2->tot_len = tot_len; 1315 p = (char *)(opt2 + 1); 1316 1317 ipv6_renew_option(IPV6_HOPOPTS, &opt2->hopopt, 1318 (opt ? opt->hopopt : NULL), 1319 newopt, newtype, &p); 1320 ipv6_renew_option(IPV6_RTHDRDSTOPTS, &opt2->dst0opt, 1321 (opt ? opt->dst0opt : NULL), 1322 newopt, newtype, &p); 1323 ipv6_renew_option(IPV6_RTHDR, 1324 (struct ipv6_opt_hdr **)&opt2->srcrt, 1325 (opt ? (struct ipv6_opt_hdr *)opt->srcrt : NULL), 1326 newopt, newtype, &p); 1327 ipv6_renew_option(IPV6_DSTOPTS, &opt2->dst1opt, 1328 (opt ? opt->dst1opt : NULL), 1329 newopt, newtype, &p); 1330 1331 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + 1332 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + 1333 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); 1334 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); 1335 1336 return opt2; 1337 } 1338 1339 struct ipv6_txoptions *__ipv6_fixup_options(struct ipv6_txoptions *opt_space, 1340 struct ipv6_txoptions *opt) 1341 { 1342 /* 1343 * ignore the dest before srcrt unless srcrt is being included. 1344 * --yoshfuji 1345 */ 1346 if (opt->dst0opt && !opt->srcrt) { 1347 if (opt_space != opt) { 1348 memcpy(opt_space, opt, sizeof(*opt_space)); 1349 opt = opt_space; 1350 } 1351 opt->opt_nflen -= ipv6_optlen(opt->dst0opt); 1352 opt->dst0opt = NULL; 1353 } 1354 1355 return opt; 1356 } 1357 EXPORT_SYMBOL_GPL(__ipv6_fixup_options); 1358 1359 /** 1360 * fl6_update_dst - update flowi destination address with info given 1361 * by srcrt option, if any. 1362 * 1363 * @fl6: flowi6 for which daddr is to be updated 1364 * @opt: struct ipv6_txoptions in which to look for srcrt opt 1365 * @orig: copy of original daddr address if modified 1366 * 1367 * Returns NULL if no txoptions or no srcrt, otherwise returns orig 1368 * and initial value of fl6->daddr set in orig 1369 */ 1370 struct in6_addr *fl6_update_dst(struct flowi6 *fl6, 1371 const struct ipv6_txoptions *opt, 1372 struct in6_addr *orig) 1373 { 1374 if (!opt || !opt->srcrt) 1375 return NULL; 1376 1377 *orig = fl6->daddr; 1378 1379 switch (opt->srcrt->type) { 1380 case IPV6_SRCRT_TYPE_0: 1381 case IPV6_SRCRT_STRICT: 1382 case IPV6_SRCRT_TYPE_2: 1383 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr; 1384 break; 1385 case IPV6_SRCRT_TYPE_4: 1386 { 1387 struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)opt->srcrt; 1388 1389 fl6->daddr = srh->segments[srh->segments_left]; 1390 break; 1391 } 1392 default: 1393 return NULL; 1394 } 1395 1396 return orig; 1397 } 1398 EXPORT_SYMBOL_GPL(fl6_update_dst); 1399